PROJECT SUMMARY/ABSTRACT Altered metabolism is a hallmark of tumorigenesis. It has been shown in various cancers that inhibition of essential metabolic pathways is a clear therapeutic opportunity. Intriguingly, altered metabolism appears to be context- and oncogene-dependent. Therefore, the efficacy of targeting metabolism will depend upon understanding its dysregulation in terms of specific oncogenes in particular tissues. Despite advancements in targeted therapeutics, breast cancer remains the most diagnosed cancer type and second leading cause of cancer-related death in women in the United States. Our lab has demonstrated that the oncogene c-MYC (MYC) is overexpressed in the majority of triple-negative breast cancer (TNBC), the most clinically challenging subtype of breast cancer. MYC is a transcription factor known to regulate diverse cellular processes including metabolism. However, the role of MYC in TNBC metabolism remains largely unknown. Our lab recently discovered that primary MYC-overexpressing TNBC displays increased bioenergetic reliance upon fatty acid oxidation (FAO), and that inhibition of FAO is a novel therapeutic strategy to treat MYC- overexpressing TNBC (Camarda et al 2016 In press ? Nature Medicine). For the F99 phase of this fellowship, I propose to investigate the molecular mechanism of FAO dysregulation by MYC in TNBC, and determine if FAO is a conserved metabolic alteration in metastatic disease. Due to the physical proximity of primary breast cancer to the adipose-rich mammary gland, we hypothesize that increased fatty acid uptake via SLC27A6 is facilitating FAO in a MYC-dependent manner, and that FAO is conserved in metastases to fatty microenvironments but not lean microenvironments. My experimental strategy combines: fluorescent techniques to image fatty acid uptake in vitro, mass spectrometry-based metabolomic analyses, single-cell mRNA expression analyses, pharmacological and genetic perturbation of metabolism, and conditional and constitutive MYC-overexpressing TNBC cell lines and mouse tumor models. I expect that the investigation of mechanisms and conservation of FAO in MYC-overexpressing TNBC will identify novel therapeutic targets to treat both primary and metastatic disease. For the K00 phase of this fellowship, I propose to leverage the broad range of conceptual and technical expertise I have amassed studying metabolic dysregulation during viral infection as an undergraduate, and in MYC-overexpressing TNBC as a graduate student to complete a postdoctoral fellowship further studying metabolism in tumorigenesis. Specifically, I will combine my previous research experience with advanced training in miscroscopy, biochemistry, bioinformatic, and mass spectrometry-based techniques to provide new insight into the functional role of dysregulated lipid metabolism in cancer. My goal is to investigate the inter- and intracellular flow of lipids in tumors, and discern functional relationships between dysregulated lipid metabolism and cellular processes to identify new therapeutic strategies to target metabolism in cancer. !